Characterization and optimization of material properties during synthesis and processing are frequent problems in materials science and engineering. In the present paper, the use of design of experiments (DOE) to characterize and improve coercivity in cobalt ferrite nanoparticles is described. The sequence of experiments was planned to capitalize on previous experimental runs available. Emphasis is placed on the rationale for choosing the additional runs. The results reveal that the choice of an adequate initial experimental design can save effort and resources in arriving at useful conclusions upon which subsequent experimental runs can be planned, capitalizing on the initial experimental structure. A region with attractive solutions in terms of coercivity, including a local maximum, was identified through the experimental sequences described in this case study. © 2011 Authors.